KR20120018738A - Plmn selection method and mobile communication device utilizing the same - Google Patents

Abstract

A PLMN selection method and a mobile communication device using the method are provided. The PLMN selection method is performed by a mobile communication device connected to the service network for emergency bearer service via an emergency packet data connection, which can access a SIM card containing a prohibited PLMN. The PLMN selection method includes receiving an equivalent PLMN list from the service network that includes the prohibited PLMN, and removing the prohibited PLMN from the equivalent PLMN list after the emergency bearer service is terminated.

Description

PLMN selection method and mobile communication device using this method {PLMN SELECTION METHOD AND MOBILE COMMUNICATION DEVICE UTILIZING THE SAME}

This application claims the priority of US Provisional Application No. 61 / 376,002, filed August 23, 2010, which is hereby incorporated by reference in its entirety.

The present invention relates generally to mobile communication systems, and more specifically to handling PLMN selection procedures for emergency and non-emergency services after an emergency service has been completed.

In a typical mobile communication environment, user equipment (UE) may communicate voice and / or data signals with one or more service networks via a cellular station of the service network. The wireless communication between the UE and the service network includes GSM (Global System for Mobile communication) technology, General Packet Radio Service (GPRS) technology, Enhanced Data rates for Global Evolution (EDGE) technology, Wideband Code Division Multiple Access (WCDMA) technology, CDMA (CDMA) Ability to comply with various wireless technologies such as Code Division Multiple Access (2000) technology, Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) technology, Worldwide Interoperability for Microwave Access (WiMAX) technology, Long Term Evolution (LTE) technology, etc. .

In the cellular communication network described above, network selection is operated by a service network that broadcasts a Public Land Mobile Network (PLMN) identity (ID). The UE may perform automated network selection based on the preferences of the PLMN IDs stored in a GSM subscriber identity module (SIM) or universal subscriber identity module (USIM). In the automated selection mode, the PLMN is selected by the UE from the preferred PLMN list with a predetermined priority. Typically, the UE also includes a forbidden list, which includes a list of PLMN IDs that are not allowed to use under normal data service conditions. Typically the UE may delete any PLMN ID present in the forbidden list from the preferred PLMN list prior to network selection, so the UE will not select the forbidden PLMN for normal data service. However, in the case of emergency services, the forbidden PLMN is not removed from the preferred list, so that the UE can select the forbidden PLMN for registration, which can cause problems when selecting a PLMN for non-emergency services. Therefore, there is a need for a PLMN selection method for selecting a PLMN for emergency and non-emergency services and mobile communication using this method.

In one aspect of the invention, a method for handling an equivalent PLMN list is disclosed. This method is performed by a mobile communication device having a packet data connection with a service network for emergency bearer service and storing forbidden PLMN identity. The method includes receiving an equivalent PLMN list from the service network including the forbidden PLMN identity; Removing the forbidden PLMN identity from the equivalent PLMN list after the emergency bearer service is completed.

In another aspect of the present invention, a PLMN selection method is provided, which method is performed by a mobile communication device having a packet data connection with a service network for an emergency bearer service and storing forbidden PLMN identity. The PLMN selection method includes receiving an equivalent PLMN list from the service network including the forbidden PLMN identity; Prohibiting selecting the forbidden PLMN identity from the equivalent PLMN list after the emergency bearer service is completed.

In another aspect of the invention, a mobile communication device having a packet data connection with a service network for an emergency bearer service is provided. The mobile communication device includes a memory that stores the forbidden PLMN identity; A wireless module for receiving an equivalent PLMN list from the service network; And a controller module to remove the forbidden PLMN identity from the equivalent PLMN list after the emergency bearer service is completed.

 In another aspect of the present invention, a mobile communication device having a packet data connection with a service network for an emergency bearer service is disclosed. The mobile communication device includes a memory that stores the forbidden PLMN identity; A wireless module for receiving an equivalent PLMN lease from the service network; And selecting the forbidden PLMN identity from the equivalent PLMN list after the emergency bearer service is completed.

Other aspects and features of the present invention will become apparent to those skilled in the art upon review of the following description of specific embodiments of apparatus, systems and methods for handling PLMN selection for emergency and non-emergency services.

The present invention removes prohibited PLMN IDs from an equivalent list after the emergency service is terminated, thereby preventing the mobile communication device from requesting an invalid PLMN registration, thereby increasing selection efficiency and reducing delays for providing communication services. Provide effect.

The invention can be more fully understood by reading the following detailed description and examples with reference to the accompanying drawings.
1 is a block diagram depicting a mobile communication environment in accordance with an embodiment of the present invention.
2 is a flow diagram of an exemplary PLMN selection method 2 in accordance with the present invention.
3 is a flow chart of another exemplary PLMN selection method 3 in accordance with the present invention.

The following description is in an optimally designed form for carrying out the invention. This description is for the purpose of describing the general principles of the invention and should not be taken in a limiting sense. The 3GPP specification is used to teach the spirit of the present invention, and the present invention is not limited thereto.

1 is a block diagram depicting a mobile communication environment in accordance with an embodiment of the present invention. In the mobile communication environment 100, the mobile communication device 110 is wirelessly connected to the service network 320 to obtain a mobile communication service. The service network 120 may include a General Packet Service (GPRS) network, a Universal Mobile Telecommunication System (UMTS) network, or a Long Term Evolution (LTE) network. The service network 120 includes a cellular station 121 and a control node 122, which is controlled by the control node 122 to perform the function of wireless transmission and reception for the service network 120. . The control node 122 is also connected to the core network 123 to interface with an external network, such as a public switched telephone network (PSTN), or to interface with an Internet Protocol (IP) based network, such as the Internet. Mobile communication device 110 may be any device used directly by an end user to communicate, such as, for example, a handheld cell phone, a laptop computer equipped with a broadband network adapter, or any other device capable of communicating. Device. The mobile communication device 110 includes a wireless module 111 for performing wireless transmit / receive functions to and from the cellular station 121. For clarity, the wireless module 111 may include a baseband unit (not shown) and a radio frequency (RF) unit (not shown). Baseband units provide multiple hardware devices to perform baseband signal processing including analog-to-digital conversion (ADC) / digital-to-analog conversion (DAC), gain adjustment, modulation / demodulation, encoding / decoding, and the like. It may include. The RF unit may receive an RF radio signal, convert the received RF radio signal into a baseband signal processed by the baseband unit, or receive a baseband signal from the baseband unit, and later receive the received baseband signal. It can be converted into a transmitted RF radio signal. The RF unit may also include a number of hardware devices to perform radio frequency conversion. For example, the RF unit may include a mixer for multiplying the baseband signal by a carrier wave oscillating at a radio frequency of the wireless communication system, where the radio frequency may be 900 MHz, 1900 MHz, or 2100 MHz used in a WCDMA system. Or 9000 MHz, 2100 MHz, or 2.6 GHz used in an LTE system, or may be a different frequency depending on the radio access technology (RAT) used. In addition, the mobile communication device 110 may include a wireless module 111 and other functional components such as a display unit and / or keyboard that acts as a man-machine interface (MMI), a storage unit that stores program code of an application or technology, and the like. A controller module 112 for controlling the operation. In one embodiment, the service network 120 may be a WCDMA system, and the mobile communication device 110 may be a UE that complies with the TS 24.008, TS 23.122 specification, and other related specifications of the WCDMA technology. Alternatively, mobile communication device 110 may be a UE that conforms to both WCDMA or LTE technology specifications, but the present invention is not limited to these specifications.

Upon entering the mobile communication environment 100, the presence of the mobile communication device 110 is known by the service network via a GPRS or PS attach procedure, where the term “GPRS connection” is used in a GPRS system, and the PS The connection is used in a UMTS or LTE system. After the GPRS or PS connection procedure is terminated, the mobile communication device 111 receives a list of PLMN IDs from the service network 120 in an ATTACH ACCEPT message, which is called an equivalent PLMN list. It is referred to. Mobile communication device 110 stores an equivalent PLMN list in SIM card 113 or any other local memory. The PLMN is a service network comprised of an access network comprising a cellular station 121, a control node 122, and a core network 123. Each PLMN is uniquely identified by a PLMN ID, which consists of a Mobile Country Code (MCC) and Mobile Network Code (MNC), where the MCC indicates the country where the network is located, and the MNC is within the country. Identifies the network. Each PLMN within an equivalent PLMN risk is equivalent to each other for PLMN selection and reselection, cell selection or reselection, and handover procedures. In the same implementation, a network operator who owns both GSM and UMTS networks in the same country or in different countries may use different PLMN codes for each network, and each PLMN code uses mobile communication device 110 to access. Hazards are collected from an equivalent PLMN list. In another implementation, a mobile network shared by multiple network operators for optimization of wireless range is also included in the equivalent PLMN list. The mobile communication device 110 can select a cell or PLMN belonging to an equivalent network regardless of the radio access technology.

After the GPRS / PS connection procedure, the mobile communication device 110 performs PLMN selection to retrieve the PLMN from the equivalent PLMN list to obtain a data service. The mobile communication device 110 performs PLMN selection each time it is switched on, when recovering from lack of coverage conditions, or when the mobile subscriber requests PLMN reselection. The PLMN selection procedure can be automatic or manual and conforms to 3GPP specification TS 23.122. The mobile communication device 110 has a number of lists (including an equivalent PLMN list and a prohibited PLMN list) stored on the SIM card 113 (or any other local memory), which list finds the PLMN. It helps to The equivalent PLMN list is a list of preferred roaming networks that are typically recorded into the SIM card by the home PLMN network operator. At the top of this list is the network where the mobile communication device 110 was last registered, and this network is automatically placed at the top of the list when the mobile station registers with an external network. The mobile communication device 110 will always search for this PLMN first, and then search for the HPLMN, then another network on the equivalent list. The forbidden PLMN list is a list of PLMNs that the mobile station attempted to register but were rejected because there was probably no roaming agreement between the home PLMN and the external network.

The forbidden PLMN list in the SIM card 113 is not removed when the mobile communication device 110 is switched off or the SIM information is extracted. The optional extension of the forbidden PLMN list may be stored in local memory (not shown) of the mobile communication device 110. If the mobile communication device 110 finds a PLMN registered in the forbidden list while searching for a PLMN for non-emergency services, the mobile communication device will reject this PLMN from the PLMN selection process. While searching for a PLMN for emergency services, the mobile communication device 110 will find the PLMN from the equivalent PLMN list regardless of the forbidden PLMN list. Both emergency and non-emergency services can be bearer services or teleservices, and can be of the type of circuit switched or packet switched. In a particular example, the emergency services are IMS call service and bearer service. IMS emergency services are indicated in the connection procedure by connection type "GPRS emergency connection". For manual mode PLMN selection, mobile communication device 110 presents all discovered PLMNs to the subscriber, including forbidden PLMNs. The Forbidden PLMN ID will be removed from the Forbidden PLMN list when registration is successful during the PLMN selection process.

Typically, a mobile communication device maintains a forbidden PLMN ID in its equivalent PLMN list when registering for emergency services. Since the prohibited PLMN ID remains in the equivalent PLMN list, the mobile communication device may select the prohibited PLMN ID for non-emergency service after the emergency service is terminated. Registration may be denied again, and the mobile communication device may take time to search for another PLMN to camp on. As a result, the PLMN selection and registration process is delayed, thus delaying the provision of emergency services.

In the present invention, the mobile communication device 110 is prohibited from selecting a PLMN ID for non-emergency services in the forbidden list after the emergency service is completed. In a particular embodiment, the mobile communication device 110 removes the forbidden PLMN ID from the equivalent PLMN list upon completion of the emergency service. In another implementation, communication device 110 removes the forbidden PLMN ID from the equivalent PLMN list before switching off the device. In another implementation, communication device 110 removes the forbidden PLMN ID from the equivalent PLMN list when the device is switched on. In another implementation, the communication device 110 selects the PLMN ID from the equivalent PLMN list, but not within the forbidden PLMN list after the emergency service is terminated. The PLMN selection procedure according to the present invention is described in FIGS. 2 and 3.

2 is a flowchart of an exemplary PLMN selection method 2 according to the present invention incorporating the mobile communication device 110 of FIG. 1.

At startup, the mobile communication device 110 is connected to the service network 120 (S200) and selects a PLMN to establish an emergency PDN connection S202. If the PLMN registration is successful, the controller module 112 performs a PDP / PDN situation activation procedure to establish an emergency packet data connection between the mobile communication device 110 and the service network 120 and receives an emergency IMS call service. . Mobile communication device 110 receives an equivalent PLMN list from service network 120 in a connection accept message or a routing area update accept message S204. A connection accept message is received in a GPRS / PS connection procedure and a routing area update accept message is received in a routing area update procedure to signal the end of this procedure. The GPRS / PS connection procedure occurs when a mobile communication device requests a packet based data service including emergency and emergency types. The connection type is labeled "GPRS emergency connection" to indicate an emergency packet based connection request. The routing area update procedure occurs when a GPRS / PS connected mobile communication device enters a new routing area and wants to notify the service network 120 of the new location. In case of an emergency IMS call, the controller module 112 returns the connection accept message or routing area update accept message with the equivalent PLMN list including one or more members of the prohibited PLMN list. Keep the prohibited PLMN IDs in this list for PLMN selection. Once the emergency service has ended, the controller module releases the emergency packet data connection by deactivating the local PDP / PDN situation associated with the emergency call service, and the wireless module 111 transmits the PDP by sending a deactivation request message to the service network S120. Start the / PDN situation deactivation procedure, and releases the emergency packet data connection for emergency services at both ends (S206). After the emergency service is terminated and the emergency data connection is released, the controller module 112 removes the prohibited PLMN ID from the equivalent list (S208) so that the prohibited PLMN is no longer selected for the next packet data service. Then, the PLMN selection method 2 is finished. In a particular embodiment, the controller module 112 detects the prohibited PLMN ID just after the end of the emergency service. In another implementation, the communication device 110 removes the forbidden PLMN ID during the switch off procedure. In another implementation, the communication device 110 removes the forbidden PLMN ID during the switch on phase.

The present invention removes prohibited PLMN IDs from an equivalent list after the emergency service is terminated, thereby preventing the mobile communication device from requesting an invalid PLMN registration, thereby increasing selection efficiency and reducing delays for providing communication services. A PLMN selection method for a mobile communication device is provided.

3 is a flowchart of another exemplary PLMN selection method 3 according to the invention incorporating the mobile communication device 110 of FIG. 1. Steps S300 to S306 are the same as steps S200 to S206 of the PLMN selection method 2 and will not be described again for brevity. In step S310, when requesting an emergency service, the controller module 112 selects a normal PLMN ID from an equivalent PLMN list, not any member in the forbidden PLMN list. In a particular implementation, the controller module 112 selects a PLMN ID from an equivalent list, compares this selected ID with a list in the forbidden list, and requests PLMN registration only when the selected PLMN ID is not in the forbidden list. In one embodiment, the controller module 112 selects a normal PLMN for non-emergency services immediately after an emergency service. In another embodiment, the controller module 112 selects a normal PLMN for non-emergency services when the mobile communication device 110 is powered on.

The present invention selects PLMN IDs from an equivalent list of non-prohibited IDs after the emergency service is terminated, thereby increasing selection efficiency and preventing communication by requiring the mobile communication device to request an invalid PLMN registration for non-emergency services. Another PLMN selection method for a mobile communication device that reduces delay for providing a service is provided.

The various illustrative logic blocks, modules, and circuits described in connection with the description of the present invention may be general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate array signals (FPGAs), or other programmable devices. It may be implemented or performed using logic device, discrete gate or transistor logic, discrete hardware components, or any combination of the above components designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine.

Although the invention has been described in terms of illustrations and preferred embodiments, it is to be understood that the invention is not limited to the described embodiments. On the contrary, it is intended to cover arrays similar to the various variations (obvious to those skilled in the art). Therefore, the breadth of the appended claims should be accorded the widest interpretation so as to encompass such modifications and similar arrangements.

110: mobile communication device
111: wireless module
112: controller module
113: SIM card
121: cellular station
122: control node
123: core network

Claims (13)

A method for handling an equivalent PLMN list performed by a mobile communication device having a packet data connection with a service network for emergency bearer services and storing forbidden Public Land Mobile Network (PLMN) identities.
Receiving an equivalent PLMN list from the service network including the forbidden PLMN identity;
Removing the forbidden PLMN identity from the equivalent PLMN list after the emergency bearer service is completed.
A method for handling an equivalent PLMN list, including. The method of claim 1, further comprising releasing the packet data connection from the service network.
And removing the forbidden PLMN identity from the equivalent PLMN list after the packet data connection is released. The equivalent PLMN list of claim 1, wherein the removing comprises removing the forbidden PLMN identity from the equivalent PLMN list when the mobile communication device is switched off or powered on. How to. The method of claim 1, wherein the removing step is executed before a PLMN selection procedure occurs. A PLMN selection method performed by a mobile communication device having a packet data connection with a service network for an emergency bearer service, and storing a forbidden PLMN identity.
Receiving an equivalent PLMN list from the service network including the forbidden PLMN identity;
Prohibiting selecting the forbidden PLMN identity from the equivalent PLMN list after the emergency bearer service is completed.
Comprising, PLMN selection method. The method of claim 5,
Releasing the packet data connection from the service network;
And the mobile communication device is prohibited from selecting the forbidden PLMN identity from the equivalent PLMN list after the packet data connection is released. 6. The method of claim 5, wherein when the mobile communication device is powered on, the mobile communication device is prohibited from selecting the forbidden PLMN identity from the equivalent PLMN list. A mobile communication device having a packet data connection with a service network for an emergency bearer service, comprising:
A memory that stores the forbidden PLMN identity;
A wireless module for receiving an equivalent PLMN list from the service network;
A controller module that removes the forbidden PLMN identity from the equivalent PLMN list after the emergency bearer service is completed.
And a mobile communication device. 10. The apparatus of claim 8, wherein the wireless module also sends an inactivation message to the service network to release the packet data connection, and the controller module is configured to disable the prohibition from the equivalent PLMN list after the packet data connection is released. Removing the PLMN identity. The mobile communication device of claim 8, wherein the controller module removes the forbidden PLMN identity from the equivalent PLMN list when the mobile communication device is switched off or powered on. A mobile communication device having a packet data connection with a service network for an emergency bearer service, comprising:
A memory that stores the forbidden PLMN identity;
A wireless module for receiving an equivalent PLMN list from the service network;
After the emergency bearer service is completed, select the forbidden controller module from selecting the forbidden PLMN identity from the equivalent PLMN list.
And a mobile communication device. 12. The PLMN list of claim 11, wherein the wireless module also sends an inactivity message to the service network to release the packet data connection, and the controller module is further configured to disable the PLMN list from the equivalent PLMN list after the packet data connection is released. Selecting the device is prohibited. The mobile communication device of claim 11, wherein the controller module is prohibited from selecting the forbidden PLMN identity from the equivalent PLMN list when the mobile communication device is powered on.

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